Greetings,
As far as "friendly" games go, we have always allowed the spliting of Slow fire weapons shots, be it titan plasma weapons or units such as bombards. I know that is comparing units with slow fire Vs a single wpn system, but either way does not seem to unbalance the list too much.
I personally see no reason rule wise or fluff/theory wise, why a titan or any other unit with multiple slow fire shots cannot spread them out. Fire discipline alows you to keep plugging away each turn with reduced effect, or you can go full auto and lay down the hurt... rambo style, but unlike rambo you have to reload

Finally I'm getting ready for a 3000pt game this week, and thinking of taking AMTL for a spin.
So far have:
Warlord
+ Vortex Missile
+ Gatling Blaster
+ Apoc ML
+ Volcano Cannon
Warlord
+ 2x Melta Cannon
+ CCW
+ Laser Burner
To this i'll add 1 or 2 flights of thunderbolts, and some upgrates to the titans. I can put together most unit types, is there anything in particular people would like me to try?
cheers